It's not like ritual combat is unheard of IRL. Perhaps the extremely dangerous light-show IS the point? Spam ridiculous amounts of glare everywhere, some judge in orbit checks who's making the biggest lens-flare? Ground combat in heavily shielded spacesuits (thanks to the noxious atmosphere) where the dazzle effects are used to attack or hurt opponents on the ground?

Hell, you could even go with a society that has been doing this for centuries, until some smarty-pants from the neighboring system flips the table by using MISSILES. Shit just got real.

(I mean I get that laser combat in an atmosphere is slightly silly, I'm just theorycrafting here for literary purposes)

Care to point to an example in the industrial-lawyer age? That's kind an idea that was going out the door an awful lot of centuries ago because by nature it requires people to believe in very formal class distinction to mean anything. Also people would just cheat the hell out of it. God only knows people cheat at everything they possibly can; one of the points of a duel with swords is you really can't cheat it. Throw sand in the eyes maybe, but that's very obvious and still requires some level of skill to win the fight doing it.

Perhaps the extremely dangerous light-show IS the point?

Instantaneously permanent blindness isn't going to groom anyone's sense of honor or courage me thinks, and if you encourage that kind of combat then the real way to do it is to make artillery shells containing a binary chemical agent that basically turns the payload into an instantaneous chemical laser light flash. Blind a whole area in one shot. Also start fires if it has enough power. This isn't notional, weapons like that reaching the test stage are why the laser blinding treaty was signed in real life. Also you would still be better off using IR lasers for blinding, because again, they penetrate obscuration better, and the human eye has no blink reflex to protect itself from slight exposure. Which means since IR light still does reflect, just not as well as visual, much smaller amounts of reflection are still going to cause eye damage. Very low power IR lasers can cause eye damage because of this.

I've never seen sci fi deal with this topic worth a damn actually, for pretty much the same reasons why we banned in IRL, not to mention people also generally don't want to deal with tactical nuclear warfare, which is the logical countermeasure to mass indiscriminate blinding on the battlefield.

Spam ridiculous amounts of glare everywhere, some judge in orbit checks who's making the biggest lens-flare? Ground combat in heavily shielded spacesuits (thanks to the noxious atmosphere) where the dazzle effects are used to attack or hurt opponents on the ground?

Who would be the judge, and why would you accept their ruling over who had a bigger lens flare in fake combat instead of just settling the dispute directly? Or holding a trade show. If nobody is going to die the idea of ritual combat is extremely lacking in meaning, particularly if we are talking about groups opposing each other with more then a few hundred members.

If you have heavy space suits, then you've already jumped into the world of powered visual devices where like I said before, you can go use a computer to add any coloring effects you want to laser beams detected in non visual wavelengths. For storywriting that could be interesting and help convey the setting and the characters reactions; such as you could have audio cues added, and ways to distinguish outgoing and incoming beams and glint vs direct viewing that wouldn't be apparent to a naked human eye. All kinds of stuff can be filtered out completely too, and electronic phased array sensors are much harder to 100% blind then eyeballs. But this doesn't require using sub optimal combat technology at all where the character just goes 'MY EYES!' and now needs 24 months of rehab to learn how not to fall down the stairs while they wait for cloned eyes to be grown in a custom mutated gene spliced pig surrogate.

Hell, you could even go with a society that has been doing this for centuries, until some smarty-pants from the neighboring system flips the table by using MISSILES. Shit just got real.

Yeah somehow I don't see that lasting centuries. Not after the ritual combat gets delayed by FOG. In the end I think people should write anything they think makes a good story, but illogically ritualized industrial age combat is a pretty tired cliche to me, and incredibly unlikely when you consider how much money it costs to build and field weapons and how more and more internet focused real life is getting. Honestly settling disputes by video game might be plausible, but if you wanted simulation champion combat in the year 2,500 you could just simulate entire battlespaces and detailed vehicle designs anyway. And plus, to mean anything we need viewers, whom are going to be watching on whatever replaces TV..and that's back to the electronic special effects studio again!

"This cult of special forces is as sensible as to form a Royal Corps of Tree Climbers and say that no soldier who does not wear its green hat with a bunch of oak leaves stuck in it should be expected to climb a tree"
— Field Marshal William Slim 1956